Creatine amidinohydrolase is an enzyme which catalyzes hydrolysis of creatine into sarcosine and urea. This enzyme can be used as a diagnostic reagent for a wide variety of diseases including kidney diseases to quantify creatine in human serum or urine.
However, the conventional creatine amidinohydrolase is disadvantageous because its stable pH range is limited to pH 4.5-8.5 so that its purification is difficult at pH values higher than pH 8.5, and its high Km value leads to the necessity of a long time to measure a sample.
Under such circumstances, the present inventors found that a novel creatine amidinohydrolase with low Km value stable in high pH range can be obtained from Alcaligenes sp. KS-85 (FERM BP-4487) cultured in medium containing creatine, and they applied a patent for the enzyme (Japanese Patent Application No. 318675/1993).